1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, apparatus and methods of controlling call establishment.
2. Background
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA), which provides higher data transfer speeds and capacity to associated UMTS networks.
It may be desirable for a radio access network (RAN) Node, such as a cellular or Wireless Wide Area Network (WWAN) base station or NodeB, to offload traffic to another radio access technology (RAT) access node, such as a WiFi or Wireless Local Area Network (WLAN) access point, capable of supporting the traffic. Existing solutions include a network access stratum (NAS)-based function, referred to as an access network domain selection function (ANDSF), and upper layer/operating system (OS)-based functions. Such existing solutions make determinations based on static rules for call establishment.
As such, in such conventional systems, it is not possible to control, from within the cellular RAN, an idle UE that is camping on the cellular network, in order to direct the idle UE to establish a new packet-switched (PS) call using, for example, a WiFi access point, rather than a cellular access point. Similar issues exist for UEs in some reselection states in, for example, UMTS. In other words, a UE cannot be dynamically directed to establish a call using a non-cellular-based access point in order to offload new traffic related to a newly-established call from the RAN node when possible.
Thus, improvements in call establishment are desired.